WHAT IS CATARACT?
Cataract is an opacity in the lens of the eye.In a camera, an object is focussed onto the film by a lens. Similarly, an object seen by the eye is focussed onto the retina by the it's lens. When the lens of our eye gets opaque, it is called CATARACT. The normal lens allows light to reach the retina. When it becomes opaque and does not allow light to reach the retina, we are unable to see clearly.
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To understand cataract better, imagine photographing through a camera with grease smeared onto it's lens. In such a case, the image formed is very hazy and blurred. Similar to grease smearing onto the lens of a camera, if the lens of the eye gets opaque, the image formed on the retina will be blurred and one will not see clearly.
HISTORY OF CATARACT SURGERY
The history of cataract dates back to 3000 years. The earliest cataract operation was performed by the famous surgeon of ancient India, SUSRUTA, a disciple of Danavantri. Even in that ancient era, Susruta described Cataract as an opacity of the lens. He had given an admirable account of the technique of its treatment by couching which he successfully practiced. In this operation he displaced the opaque cataractous lens away from the centre of the eye to another part of the eye. Today modern medical advances have made cataract surgery one of the most successful forms of surgery. New surgical techniques and Intraocular lenses can restore excellent vision in 97% of all cases. In the 1960's Dr.Charles Kelman from USA started a technique called Phacoemulsification in which cataracts were removed through a 3 mm incision, compared to a 12 mm incision in which the whole cataract was removed in toto. Then in 1998, Dr.Amar Agarwal from India started a technique called PHAKONIT in which cataracts were removed through a 1.0 mm opening. In the year 2001 a special lens was made which went through this small opening of 1 to 1.5 mm. This was called the Rollable Intraocular lens.
WHY DOES CATARACT FORM?
The causes of the formation of cataract are not fully known. It is basically an aging phenomenon. Just as our hair gets grey, so also does the lens of our eye get opaque. Next to old age come other factors like deficiency of food like proteins and vitamins, some toxic drugs, general diseases like diabetes, infections and injuries. Sometimes German measles in pregnant mothers causes cataract in the child.
TIPS BENEFICIAL TO DELAY THE ONSET OF CATARACT
- Take good and nourishing diet rich in proteins and vitamins. Food such as liver, eggs, milk products, carrots, cabbages and yeast are good.
- Protect your eyes from excessive exposure to sunrays, X-rays, intense heat and injuries.
- Diseases such as Diabetes and syphillis should be treated early
and effectively.
TREATMENT OF CATARACT
THERE IS NO MEDICAL TREATMENT FOR CATARACT. THE ONLY TREATMENT IS SURGERY. The important question is when should one get operated for cataract. This depends on the occupation of the patient. If the patient is a pilot, he should be operated earlier for slight deterioration of vision will affect his work, whereas if the patient is a housewife, she can delay surgery for some time. When a person has a cataract and the decision is made to operate, then the diseased lens is removed and replaced by an artificial lens.
ALTERNATIVES OF THE NATURAL LENS
Once the cataract [diseased lens] is removed, there is no focussing ability of the eye as there is no lens in the eye. So one has to use an artificial lens to get the object focussed onto the retina. This can be either in the form of a spectacle, contact lens or an Intraocular lens.
- Spectacles can be used but these are very heavy and not comfortable. Further, if one removes these glasses the person is blind. Other disadvantages of these glasses is that everything is magnified and the side view is very poor.
- The second alternative is to use a Contact lens. This is an artificial lens placed on the eye. The disadvantage as with spectacles is that if we remove it the person is blind as there is no focussing ability. Another problem with contact lenses is that they have to be put on in the morning and removed at night which is difficult for an old person.
- So, the best method is to give the patient an INTRAOCULAR LENS. This is an artificial lens that is placed in the eye at the time of surgery. It will remain in place till the end of life. By this all the problems of spectacles or contact lenses is removed. This lens does not irritate the eye.
MANUAL CATARACT EXTRACTION TECHNIQUE
The manual or the old technique for cataract removal use a 12 mm incision (cut) to remove the cataract. One technique called the INTRACAPSULAR CATARACT EXTRACTION has an incision of 12 mm. In this the entire cataract is removed with the capsule of the lens. The disadvantage of this technique is that the artificial lens called the Intraocular lens (IOL) is placed in the capsular bag with the capsule of the lens acting as a support for the lens. As the capsule is not present the IOL cannot be placed in the capsular bag position.
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Another manual technique is called the EXTRACAPSULAR CATARACT EXTRACTION TECHNIQUE. In this the incision is about 10 mm. In this the cataract is removed but the capsule of the lens is left behind. The advantage of this technique is that the artificial lens called the Intraocular lens (IOL) is placed in the capsular bag with the capsule of the lens acting as a support for the lens.
The disadvantage of this technique is that the incision is quite large of about 10 mm which creates scarring in the eye. This means half the eye is cut open and then an IOL is inserted inside the eye. The IOL is about 6 mm and so easily goes inside the eye. Sutures are then placed and the patient admitted. The patient takes rest for 45 days and after that suitable glasses are prescribed. The patient is given spectacles for fine tuning after 45 days.
 PHACOEMULSIFICATION
Dr.Charles Kelman from USA started a technique called phacoemulsification in the 60's to remove cataract through a 3 mm opening. Since then various new modalities have developed which have made this technique more refined. The machine for removing the cataracts is called a Phacoemulsifier machine which cuts the cataract into small pieces and removes them by aspiration.
 FOLDABLE INTRA-OCULAR LENSES
Normally, the lenses used are rigid and cannot be folded. The problem by this is that one has to make a large cut or incision in the eye to implant these lenses. Today, the latest development in Intraocular lenses is the FOLDABLE intraocular lens. These are special lenses which can be folded. Once they are folded they are placed in a special cartridge and then the cartridge is place in a special injector. The injector is passed into the eye and the lens also gradually passed into the eye. The lens unfolds in the eye. These lenses can be passed into the eye through a very small cut. Thus this foldable Intraocular lens helps make the incision very small.
PHAKONIT (Cataract surgery through a sub 1 mm incision)
One of the biggest breakthroughs in cataract removal has come from India by a technique called PHAKONIT. In this the incision is brought down from a 3 mm incision to a 1 mm incision.
The first step is to make the incision. Then the instruments for Phakonit are passed into the eye and the cataract cut into small pieces by Phakonit and finally the whole cataract removed.
The problem with this technique was to find an IOL which would pass through such a small incision. Then on October 2nd 2001 the first case of a Phakonit Rollable IOL was done.
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The lens used was a special lens from USA. This was the first Rollable IOL which was implanted after a Phakonit procedure and was a rolled IOL.
 The advantage of this lens is that it is a very thin lens and when placed in water becomes pliable and can then be rolled and inserted into the eye. Inside the eye the lens opens gradually. The patient can come to the hospital and go home immediately. The advantages are that the 1 mm barrier is broken and the incision now has become so small.
MICRO-PHAKONIT
(Cataract Removed Through A 0.7 Mm Needle)
On May 21st 2005, a new technique "MICRO PHAKONIT" has been introduced by Dr.Agarwal's Eye Hospital, Chennai whereby cataracts were removed with a specially designed needle of 0.7 mm. The surgery was carried out by Dr.Amar Agarwal, Director of Dr.Agarwal's eye hospital, Chennai, India. The instruments were designed by him and manufactured in the United States of America.
Image will come
As the incision now becomes smaller than the original phakonit technique started in 1998, the technique has been termed Micro-Phakonit. This technique is absolutely painless and the patient does not require any injection at all. Since the incision is below 1 mm the patient has no injection, no stitches and no pad. The patient walks inside the hospital and goes back immediately.
OUT-PATIENT CATARACT SURGERY
Today, we are able to operate patients with cataract and remove their diseased lenses and replace it with an artificial lens called an Intraocular lens as an out-patient procedure. The patients are not at all admitted in the hospital. The patient comes in the morning for surgery and after the operation can go home. The patients can go back to their work within a couple of days as the healing is very quick because of the ultrasmall incision.
WHAT ARE THE CHANCES OF GOOD SIGHT AFTER OPERATION?
With the advancement of cataract surgery and modern skills, the success of cataract surgery is between 97-99%. Complications like infection and haemorrhage can occur but are very rare. One should remember that if the retina or nerve of the eye are damaged then even after a good cataract operation the person will not see.
Putting large lenses in large incisions is bucking the tide of history. Small incisions offer the best chance for most-rapid, stable visual rehabilitation of the cataract patient at the least cost, including time of impaired vision following surgery, the need for follow up care, the attendance of relatives to take care of them to the doctor and the like.
SUMMARY
The advantages of performing Phakonit cataract surgery due to the very small size of the cut made in the eye is that -
- The patients are not admitted in the hospital
- The patients come for the surgery and go back immediately after a few hours in the hospital
- There are no stitches used
- The patient gets back to his or her normal routine the next day and can go to office, have a head bath or do the normal housework like cooking etc.
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Source: Dr. Agarwal's Eye Hospital, http://www.dragarwal.com
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